01Grey cement
Bags of cement per cubic metre of concrete, by grade of concrete.
50 kg bags per cubic metre
- Use OPC 53 for M25 and above.
- Keep the water to cement ratio below 0.5 for structural work.
- A 100 m² slab at 125 mm needs about 12.5 m³ of concrete.
02White cement and putty
Coverage per kilogram on a sound, level wall.
Square metres per kilogram
- Rough or wavy walls can halve these figures.
- A 20 kg bag of putty covers about 30 m² in two coats.
- Prime very porous walls first to save material.
03Mortars and plasters
How far one bag goes on walls and block work.
Coverage per bag
- Check walls for plumb first: uneven walls take more plaster.
- Thin-bed mortar needs dimensionally accurate blocks.
- For grout, volume in litres = length × width × gap in decimetres.
04Adhesives and repair
Coverage for tiling, waterproofing and patch repairs.
Coverage per bag
- Back-butter tiles larger than 600 mm.
- Waterproof before tiling in wet areas.
- Mix repair mortar in small batches: working time is 15 minutes.
05Bastion coverage guide
Rough quantities for the most common jobs. Add 5% for wastage, and ask us to check anything structural.
Based on 50 kg bags of cement
- Measure length × width × thickness in metres to get cubic metres.
- Add 5% for wastage on bagged work, 3% on bulk.
- Order structural grades in one batch where you can, for a consistent colour.
Unusual mix, or ordering by the truckload?
